Household pets, especially cats, can be trained to use a litter box which is filled with an absorbent material know as litter. Gravel, sand, and baked clay are commonly used as litter material. Conventional litter boxes generally consist of a relatively flat, open pan that has been filled with a litter material. Because the litter box is not enclosed or covered, the litter box has an unpleasant odor and appearance.
With some regularity, the pet owner must clean the litter box. However, the appearance and odor of animal waste makes the task unpleasant, and it can be physically challenging because most litter boxes are kept on the floor. If the litter box is not cleaned frequently, the odor and appearance of the litter box will worsen, and the, odor will ultimately permeate the litter box and the pet owner's house. If the litter box is not kept clean, the pet will often abandon it.
To clean the litter box, the pet owner must either discard the full contents of the litter box or separate the animal waste from the otherwise clean litter material. If the entire contents are discarded, the cost of maintaining a clean litter box is greatly increased because not all of the litter material has been contaminated. If the pet owner decides to separate the waste from the litter, he must buy a scoop or filtering device. Moreover, the owner must exercise care because the litter box, the filtering device, and the litter material are unsanitary. The litter box should also be given a chance to air out by exposing the empty box to fresh air to dry any remaining moisture and to dissipate any odors. Otherwise, continuous use will cause the odor to permanently saturate the litter box.
Several prior devices have attempted to alleviate the problems associated with litter boxes. For example, U.S. Pat. No. 5,012,765 to Naso et at. discloses an animal waste collection and screening device having two litter pans in opposed orientation with the open face of the first litter pan facing the open face of the second litter pan. A screen member is interposed between the opposing litter pans so that the waste and litter are separated when the apparatus is inverted. The inversion process can be difficult because the pet owner must lift the apparatus by hand and flip it over, and the pet owner must shake or fluff the apparatus to separate the waste from the litter material. After the separation, the pet owner must remove the filtering screen from the apparatus to discard the animal waste. During this final step and when the apparatus is in use as a litter box, the waste is not enclosed, so the apparatus has an unpleasant odor and appearance.
U.S. Pat. No. 3,908,597 to Taylor discloses a litter box that has a central receptacle divided by a partition into dual compartments that may alternatively serve as upper and lower kitty litter areas. Each compartment has its own screened tray to separate animal waste from litter, but the process involves several labor intensive steps. Moreover, the pet owner must handle the screened tray that was buried within the contaminated litter material. Finally, the Taylor device does not enclose the litter material, so the litter box has an unpleasant odor and appearance.
U.S. Pat. No. 4,886,014 to Sheriff discloses a pet litter box that purports to separate reusable litter material from solid pet droppings. The separation is accomplished by a series of tilting and rotating motions that must be followed in a precise manner. Because the apparatus is not supported by a frame, the pet owner must perform the labor intensive task in close proximity to the animal waste, and olfactory contact with offensive odors is likely. Finally, the pet entrance way does not have a door, so the litter box does not contain the animal waste odors when in use.